Jackson, Grdon E., author
Prentice-Hall, 1993
Buku Referensi
edited by Arthur M. Ross
University of California Press, 1965
Buku Teks
Artikel Jurnal
Beirne, Joseph A., author
Prentice-Hall, 1969
Buku Teks
by Akira Takanashi [and others]
The Japan Institute of Labour , 1999
Buku Teks